Chain-stitch sewing-machine.



A. H. DE VoB.l

4 CHAIN STITCH SEWING MACHINE.

APPLICATION FILED .APB.2Z, 1909- Patented Dec. 13,1910.

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WITNESSES Ano/mfr A. H. DE VoB. CHAIN STITCH SEWING MACHINE.

APPLICATION FILED APILZZ, 1809.

Patented Dec. 13, 1910.

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WIT/VESSES Mu/ff( er ATTHNEY &

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UNITED sTATns PATENT ernten.

ALBERT H. VOE, 0F ELIZABETH, NEW JERSEY, ASSIGNOR TO THE SINGER MANU-FACTURING COMPANY, A CORPORATION OF NEW JERSEY.

1 CHAIN-STITCH SEWING-MACHINE.

Specification of Letters Patent.

Patented Dec. 13, 1910.

Application led April 22, 1909. Serial No. 491,575.

To all whom 'it may concern:

Be it known that I, ALBERT H. DE Von, a citizen of the United States,residing at Elizabeth, in the county of Union and State of New Jersey,have invented certain new and useful Improvements in Chain-StitchSewing-Machines, of which the following is a specification, referencebeing had therein to the accompanying drawings.

rlhis invention has for its primary object to provide a high speedmachine adapted for producing'simultaneously a large number of parallelseams; and has for its further object to provide simple and effectivestitchforming and feeding mechanisms capable of meeting the speedrequirements of the trade at the present time.

In its preferred form, the present irnprovement comprises a machineprovided with a short main-shaft journaled at the rearward end of thebracket-arm and provided with a crank for actuating the stitchformingmechanism and imparting lifting movements to the feeding member and withan adjacent eccentric for imparting workadvancing movements to saidfeeding member.- The needle-bar derives its reciprocating movements froma rock-shaft having a i crank-arm connected with one end of a togglemember whose opposite end is connected with a second toggle memberhaving its other extremity fulcrumed upon a fixed part of the machine,the pivotal connection between the toggle members being attached to oneend of a pitman whose other end embraces theA actuatingI crank of themainshaft. The toggle and its actuating crank 4 are so proportioned thatsaid pivotal connection is moved between extreme positions substantiallyequi-distant from alinement with the outer ends of the toggle membersfor each semi-rotation of the actuating crank, which latter thus impartstwo complete reciprocations of the needle for each rotation of themain-shaft. The loop-takers, herein shown with spaced oppositelydisposed beaks arranged in the same plane for cooperation alternatelywith the same needle, are mounted upon a rock-shaft provided with acrank-arm having a pitman connection with an extension of one of saidtoggle members of the needle-actuating mechanism, uwhereby the looperrock-shaft receives one rocking movement for each two of said movementsimparted to the needle-actuating rock-shaft. The feeding member isconnected with the usual feed rocker beneath the bed-plate provided withan upwardly extending arm adjustably connected with a depending arm ofan intermediate rockshaft carrying a second arm connected with onemember of a toggle device whose other member has a fixed fulcrum andwhose pivotal connection is attached to the lower end of aneccentric-rod having at its upper end a stra embracing the eccentricupon the main-s aft which serves to impart the workadvancing movementsto the feeding member. Upon the fixed fulcrum-pin of the work-advancingtoggle mechanism is mounted an elbow-lever having a lateral armconneeted with one end of a pitman whose opposite end is connected withthe before mentioned extension of the needle-actuating toggle member,while a second depending arm of said elbow-lever forms one member of atoggle whose other member consists of a link pivotally connected theretoat one end and having the other end attached to a lateral arm of thefeed-lifting rock-shaft connected in a manner well-lmown with thefeeding member to impart thereto its lifting movements.

It will thus be seen that the mechanism above described im arts to theseveral members of the stitchlorming and feeding devices easy movementsinvolving pivotal connections throughout, and that the several parts ofthe mechanism insure the requisite power with the least expenditure ofenergy.

In factories employing various types of sewing machines, most of whichare necessarily driven at moderate speeds, it is quite important thatsuch machines as are driven at the highest speeds may be operated fromthe same line shafting and the same style of power transmitters as othermachines with which they are associated, without employment of pulleysof too large a difference in diameter for practical purposes. Byemploying a driving shaft adapted to transmit to all of the operatingparts the requisite movements for producng a plurality of stitches vforeach rotation of said main-shaft, the latter is enabled to be rotated ata. moderate speed without impairing the high speed capabilities of themachine. By this means, the wear of the main-shaft in its bearings, dueto the lateral pull of the belt which usually transmits power to saidshaft,

' vices.

is prevented from being excessive, by reason of the comparatively slowrotation of the shaft in said bearings, while the durability of saidpower-transmitting belt is greater than if it were subjected to the morerapid distortion which it receives in traveling around the pulleysconnected thereby.

The invention will be more fully understood by reference to theaccompanying drawings, in which- Figure 1 is a rear side elevation,partly in section, representing a machine provided with the present.improvements, and Fig. 2 a bottom plan view of the same. Fig. 3l is afront end elevation of the machine with the bed-plate in section, andFig. 4 a transverse section of the machine through the hollow uprightportion of the bracket-arm representing the several toggle mechanismsfor actuating the stitch-forming and feeding de- Fig. is an enlargedperspective view, partly in section, showing a set of loopers upon thelooper rock-shaft, and Fig. 6 a plan view, upon a still larger scale, ofone of the loop-taking members in its relation to the needle at theloop-seizing point.

lFig. 7 is a perspective view of a portion of the feed-actuatingmechanism, and Fig. 8 a perspective view upon a larger' scale ofl a partof said mechanism.

VThe machine is constructed with a frame comprising the usual bed-plate1 and bracket arm consisting of the hollow standard 2 and horizontalportion 3 with head 4 in which latter is journaled the rectilinearlyreciprocating needle-bar 5 carrying the multiple needle-clamp G in whichare secured the eyepointed needles 7, of which three arel shown in thedrawings. The needle-bar is provided with the usual collal.' 8 connectedby means of the pitman 9 with the outer end of a lateral arm 10 upon theneedle rock-shaft 11 journaled in bearings 12 and 13 extended from therear side of the bracket-arm. The rock-shaft 11 has fixed upon itsrearward end the depending crank-arm 14 pivotally connected by means ofthe pin 1.5 with the embracing forked end. of a link member 16 whoseforked opposite end is embraced by the forked rearward extremity of alink member 17 connected therewith by means of the pivot-al pin 18 andhaving its forward end terminating in a hub 19 embracing the iiXedfulcrum-pin 20 mounted in the standard 2 andV formed with the forwardlyprojecting arm or extension 21. The forked lower end of the link member16, which with the member 17 affords a toggle device intermediate thefulcrum-pin 20 and the pivotal pin 15 of the crank-arm 14, embraces oneend of a pitman 22, pivotally connected therewith by means of the pin18, whose opposite end is formed with a strap 23 which embraces anactuating crank 24 formed in the main-shaft 25 journaled in bearings 26and 27 ofthe bracket-arm and provided with an adjacent feed-liftingeccentric 28 intermediate said bearings. The crank 24 is so proportionedin relation to the toggle 1G 17 that it serves to bend the sameequi-distantly into extreme positions at opposite sides of its meanposition in alinement with the fulcrum members 15and19 in eachsemi-rotation of the mainshaft, whereby the 'rock-'shaft 11 receives twoequal oscillatory movements, and the needles 7 two completereciprocatory movements, for each rotation of the main-shaft, while therocking member 17, 19, 21 receives only a single oscillatory movementfor each rotation of the main-shaft. The shaft 25 has fixed upon itsrearward end t-he usual balance-wheel 29 with attached belt-wheel 30 toreceive the power transmitting belt by means of which the machine isdriven.

loperating with each of the needles 7 is a loop-taking membercomprising, as represented in the drawings, a perforated hub 31 providedwith two divergent armsr 32 and constituting shanks for the looper beaksor points 34 and 35 respectively. The primary looper beak is cut awayVupon one side to form a fiat loop-seizing blade 36 bulged upon the lowerside to form at its heel an inclined loop-detaining shoulder, and ad-4jacent said flat blade is formed with a lat eral loop-distending portion37 of such form Ythat a loop of needle-thread extending from theloop-detaining shoulder upwardly and rearwardly to the needle-hole islaterally distended by the portion 37 to admit the' needle-point in thesucceeding descent ofthe needle. The secondary loop-seizing beak 35 iswedge-shaped so as to spread the needle-loop seized by the same, and hasbeneath it a barb 38 to form an intermediate fork to detain theneedle-loop in the'advance posit-ion of this loop-taking implement andin opposition to the feeding action. The Vhub of each loop-taking memberis formed with a key-way 39 fitted to an ex ternal key or spline 40extending longitudinally of a carrying sleeve 41 which-is fitted uponthe reduced forward portion 42 of the loop-taker rock-shaft 43 journaledin bearings 44 upon the bottom of the bedplate 1. As herein shown, theshaft section 42 is provided with a threaded portion 42X to which isapplied the thrust-nut 45, against which rests one end of the extremespacing ring 46 of a series interposed be- Y tending laterally from thetoggle link extension 21 adjacent the fulcrum-pin 2() whereby the looperrock-shaft' receives a single rocking movement for every two rockingmovementsof the needle-actuating rockshaft ll.

i' 1 The feed-dog 53is secured by means of a screw 5ft upon the end of alateral arm extending from a rock-bar 56 journaled 1ntermediate theupwardly projecting arms 57 of the feed rock-shaft 5S, which has securedupon its rearward end the upwardly projecting arm 59 extending through aslot 1X in the bed-plate and formed in its upper portion with a slot 60.Journaled in a rearwardly projecting lug 61 of the standard 2 is anintermediate rock-shaft 62 having a depending arm 63 adjacent the arm 59and provided with a slot 64 entered by the transverse tongue 65 upon theinner face of the head 66 of a bolt 67 `whose shank passes through theslots of the members 63 and 59, and preferably carries a roller-stud 68einbraced by the slot 60, the said bolt being suitably shouldered topermit the roller-stud to turn when confined thereon by the nut 69. Aspacing washer 70 is interposed between the adjacent faces of the arms59 and 63. The` intermediate rock-shaft 62 is provided with a seconddepending crank-arm 71 connected by means of a screw-stud 72 with alink-member 73 of a toggle device whose other link-member 74 isconnected thereto at one end by means of the pivotal pin 75 and has itsopposite end fulcrumed upon the fixed pin 76 mounted in the standard 2.

y The link-member 73 is provided with a fork 77 in which is secured bymeans of the pin the lower end of the eccentric rod 78 whose upper'endis provided with a strap 79 embracing the eccentric 28 upon themain-shaft. The parts are so proportioned that the toggle 73 74 is bentequally in both directions twice for each rotation of the main-shaft,thereby imparting' two lateral or work-advancing movements to thefeeddo-g 53 for each rotation of the main-shaft, the extent ofoperative. movement of the feed-dog being determined by the position ofadjustment of the bolt 67 in relation to the oppositely extendingcrank-arms 59 and 63.

The feed lifting rock-shaft 80 is provided with a lateral arm 81 havinga suitable connection with a second lateral arm 82 of j to M. Hemleb,No. 863,533, of August 13, 1907.

The feed-lifting rock-shaft 80 has upon its rearward end a laterallyextending crankarm 83 connected by means of a pin 84 with the lower endof a link 85 whose forked upper end embraces and is pivotally connectedby means of the pin 86 with the depending arm 87 of an elbow-leverfulcrumed upon the pin 76 and having a lateral arm 88 carrying ascrew-stud S9 embraced by the lower end of a pitman 90 whose upper endis formed with a strap embracing the stud 91 projecting laterally fromthe forward extension 21 of the link member 17 and provided with a nut92 by which the same is confined upon said stud. As will be observed,the link 85 and arm 87 constitute the component members of a toggledevice whose pivotal pin 86 is carried from one to the other extremeposition across a line joining the pivotal pins 74 and 76 twice for eachexcursion of the rocking member 21, thereby imparting to the feed-dogtwo lifting movements for each rotation of the main-shaft synchronouslywith the double stitch-forming cycle performed in the saine period.

In the operation of the machine as thus described, the needles descendand begin to rise slowly, each presenting its thread-loop to itsrespective primary looper whose blade 36 enters the same in its advancein the direction of feed, the needle rising to its highest positionduring which rising movement the feed-dog also rises and subsequentlyperforms its work-advancing or feeding movement while the point of theneedle is still above the work, thus advancing the end of the previouslyseized needle-loop. As the needle is about to penetrate the work in asucceeding descent, the looper commences its retrograde movement,carrying with it the free end of the previously seiied needle-loopspread upon its distending portion 37 in which position of the loop thepoint of the needle enters the same, while the continued retrogrademovement of the looper effects the escape of the same upon theneedle-blade. During the return movement of the primary looper toinitial position the secondary looper advances, and as the needle beginsl to rise, seizes a second loop of needle-threzul, and holds the samedurinff the rise and feeding movement of the feed-dog, maintaining theloop distended until the point of the needle in the succeeding descententers the same, when the secondary looper recedes to leave the looparound the needleblade, the advance of the primary looper beingeffected, as before described, to seize the new loop ofthread presentedby the needle in the initial portion of its rising movement, and thealternate coperation of the primary and secondary loopers with theneedle continuing as before described.

It will be observed that the loopers enter the needle loops in oppositedirections in the `ment slightly beyond the needle path in relation toits retracted position, for holding the distended needle loop forpassage of the needle in its subsequent descent, while the primarylooper, after advancing in its loopseizing movement to extremeloop-holding position, immediately begins its retrograde movement todraw the loop backwardly in front of the needle path in opposition tothe work-feeding movement, this movement being so timed that the pointof the needle enters the distended loop upon the backwardly movinglo-oper before it is cast off the rounded lower edge of the blade 36;The described movement o-f the rock-shaft t3 is insured by disposing thepivotal pin 52 upon the member 21 laterally of the fulcrum-.pin 2O whenthe link-member 1T is in its lower position, the crank-arm ll) of thelooper-actuating rock-shaft being at this time at the corresponding sideof the rockshaft, as represented in F ig. l. its the linkmember 17 isrocked by the pitman 22, the pin 52 moves downwardly in an arcconcentric with the fulcrum-pin 20, while the crank-pin 50 moves in asimilar arc about the shaft el?) as a center'. As in the oppositeeXtreme position of the link member 17 the pin 52 crosses a lineconnecting the pivotal members 20 and 50, it will be observed that themembers 21 and 51 constitute a toggle device which is straightened inonly one eX- treme position of the actuating part 17, whereby the looperrock-shaft l-FS receives a dwell in only one of its extreme positions,

which corresponds with the advance or loopholding position of thesecondary looper By the term dwell asused herein, is meant a period ofsubstantial rest exceeding Vthe time normally required for the reversalof the circular novements in opposite directions imparted to theloop-taker shaft The machine is provided with the usual presser-footsecured to the lower end of the presser-bar @l suitably mounted in theheadd of the bracket-arm and provided with a collar 95 between which andthe bushing 96 surrounding the upper end of the presserbar is interposedthe spring 97, the usual cam-lever 98 being provided for engagement withthe arm 99 extending from the collar 95 for lifting the presser-bar.

While certain of the parts of the machine are herein minutely describedin their construction and arrangement, it is to be understood that thepresent improvement is susceptible of material modification of theseseveral features without departure from theA scope of the invention.

Having t-hus set forththe vnature of the invention, what claim hereinis 1. In a sewing machine, the combination with the main-shaft providedwith a plural-V ity of actuating members, stitch-forming f mechanismcomprising a reciprocating needle and a cooperating loop-taker, andfeeding mechanism including a work-engaging ments for each rotation ofsaid shaft, a

crank-arm upon the feed'- actuating rockshaft, an operative connectionbetween another of the actuating members of the mainshaft and saidcrank-arm for imparting to the actuating rock-shaft rocking movementscorresponding in number with t-he operative movements of saidstitch-forming mechanism, a crank-arm upon the lifting rockshaft, and anoperative connection between the toggle member having the fixed fulcrumand the crank-arm of said lifting rock-shaft for imparting operativemovements to the latter corresponding in frequency with those of saidactuating rock-shaft.

2.111 a sewing machine, the combination with the main-shaft providedwith a plurality of actuating members, stitch-forming mechanismcomprising a reciprocating needle and a cooperating loop-taker, andfeeding mechanism including a work-engaging member and actuating andlifting rockshafts having independent operative connections therewith,of means including a toggle device having one of its component membersmounted upon a fixed fulcrum and connected with one of the actuatingmembers of the main-shaft for imparting to each of the component membersof the stitch-forming mechanism YaV plurality of stitch-formingmovements for each rotation of said shaft, means connected with anotherof the actuating members ofthe main-shaft for imparting to the actuatingrock-shaft rocking movements corresponding in number with the operativemovements of the stitch-forming mechanism, and a link connection betweenthe toggle member having the fixed fulcrum and said lifting rock-shaftfor imparting to the latter rocking movements corresponding in-frequencywith those of the actuating rock-shaft.

ln a sewing machine, the combination with the main-shaft provided with aplurality of actuating members, stitch-forming mechanism comprising alreciprocating needle and a coperating loop-taker, and feeding mechanismincluding a workengaging member, of means connected with one of theactuating members of said main-shaft and including a common rockingmember for imparting to the component elementsI of the stitch-formingmechanism a plurality of stitch-forming movements for each rotation ofthe main-shaft, an operative connection intermediate said common rockingmember `and the work-engaging member for impartmg to the latter risingand falling movel5 ments, and an operative connection intermediateanother of the actuating members of the main-shaft and saidwork-engaging member' for imparting to the latter workadvancingmovements.

4l.k In a sewing machine, the combination with the frame comprising abed-plate and an overhanging bracket-arm, the main-shaft, stitch-formingmechanism including a reciprocating needle, and a coperating looptaker,and feeding mechanism including a work-engaging member, ofneedle-actuating means comprising a rock-shaft journaled `uponl anddisposed longitudinally of the bracket-arm and" operatively connectedwith the needle and provided with a crank-arm, a toggle device connectedwith said crankarm and comprising two pivotally connected members one ofwhich is provided with a fixed fulcrum, and a connection intermediatethe main-shaft and said toggle whereby the latter is alternately bent inopposite directions, means for imparting operative movements to saidloop-taker, and means for actuating `said feeding mechanism.

5. In a sewing machine, the combination with the main-shaft,stitch-formin mechanism including a reciprocating neef le and acoperating loop-taker, and feeding mechanism including a work-engagingmember, of needle actuating means comprising a rockshaft extendinglongitudinally of the bracketarm and operatively connected with theneedle and provided with a crank-arm, a toggle device connected withsaid crank-arm and comprising two pivotally connected members one ofwhich is provided with a fixed fulcrum, and a connection intermediatethe main-shaft and said toggle whereby the latter is alternately bent inopposite directions, a loop-taker operating rock-shaft parallel with theneedle-actuating rock-shaft, an operative connection intermediate one ofsaid toggle members and the loop-taker rock-shaft for imparting theretooscillatory movements, and means for actuating said feeding mechanism.

6. In a sewing machine, the combination with the main-shaft,stitch-forming mechanism including a reciprocating needle and acoperating loop-taker, and feeding mechanism including a work-engagingmember, of needlc-actuating means comprising a rockshaft operativelyconnected with the needle and provided with a crank-arm, a toggle deviceconnected with said crank-arm ande comprising two pivotally connectedmembers one of `which is provided with a fixed fulcrum and with aloop-taker actuating crankpin, a loop-taker rock-shaft provided with acrank-arm, an operative connection intermediate the main-shaft and saidtoggle whereby the .latter is alternately bent in opposite directionsand said crank-pin is caused to thereby move alternately into and out ofalinement with said fixed fulcrum and the outer end of the crank-arm ofsaid looptaker shaft, a pitman connection intermediate the last namedcrank-arm and the crankpin of said toggle member, and means foractuating said feeding mechanism.

7. In a sewing machine, the combination with stitch-forming mechanismcomprising a reciprocating needle and a loop-taking member movable in alane substantially in the line of feed and formed with -two oppositelydirected beaks, and feedingy mechanism, of means for actuating saidneedle, and means for imparting oscillatory movements to saidloop-taking member of less frequency than the needle reciprocations andincluding a dwell in the extreme position of said loop-taking member atthe end of a movement opposite the direction of feed and in excess ofthat incidental to the reversal of direction of movement in the otherextreme position.

8. In a sewing machine, the combination with stitch-forming mechanismcomprising a reciprocating needle and a loop-taking member movable in aplane substantially in the line of feed and formed with two loopseizingbeaks disposed respectively in and opposite to the direction of feed,the former having a loop-detaining shoulder at its heel, and feedingmechanism, of means for actuatino' said needle, and means for impartingoscillatory movements to said look-'taking member of less frequency thanthe needle reciprocations and including a dwell in the extreme positionof said loop-taking member at the end of a movement opposite thedirection of feed.

9. In a sewing machine, the combination with the main-shaft,stitch-forming mechanism including a reciprocating needle and acoperatino loop-taker, and feeding mechanism inclu( ing anf'ork-engaging member, of needle-actuating means comprising a toggledevice and a connection with the main-shaft for bending said toggleequi-distantly in opposite directions from .its straightened positlon,means for actuatmg said loop-taker for coperation with said needle ineach reciprocatory movement thereof, means for imparting work-advancingmovements to rae means for imparting workadvancing movements forcommunicating rising and falling movements to said work-engaging memberof the feeding mechanism of the same frequency as said work-advancingmovements.

10. In a sewing machine, the combination with the main-shaft,stitch-forming mechanismincluding a reciprocating needle' and acooperating loop-taker, and feeding mechanism including a work-engagingmember, ot needle-actuating means comprising a toggle device and aconnection with the main-shaft for bending saidV toggle equi-distantlyin opposite directions from its straightened position, means foractuating said loop-taker for cooperationr with said needle in eachreciprocatory movement thereof, means for imparting work advancingmovements to said work engaging member of the feeding mechanismand-comprising a toggle device and a connectionbetween the main-shaftand said toggle device whereby thelatter is bent equally in oppositedirections from straightcned position, and means for imparting risingand falling movements to said work-engaging member of the feedingmechanism and including a toggle device and a connec` V tion between thesame and one of the members of the needle actuating toggle devicewhereby said toggle device is bent equally in opposite directions fromstraightened position.

In testimony whereof, I have signed my name to this specification,in-the presence of 40 two subscribing witnesses.

ALBERT H. DE VUE.

lVitnesses H. A. KORNEMANN, J r., JOSEPH F. JAQUITH.

